Former Carolina Panthers teammates Mike Tolbert (35) and Thomas Davis (58) will meet again on Sunday, from opposite sidelines. Tolbert now plays for the Buffalo Bills, and will face Davis while on an opposing team for the second time in his career. Jeff Sinerjsiner@charlotteobserver.com

Former Carolina Panthers teammates Mike Tolbert (35) and Thomas Davis (58) will meet again on Sunday, from opposite sidelines. Tolbert now plays for the Buffalo Bills, and will face Davis while on an opposing team for the second time in his career. Jeff Sinerjsiner@charlotteobserver.com

Mike Tolbert has always been loud, a belly-laugher, rollicking jovially through conversations when some might have backed off.

The fullback’s first NFL game was on the road and against the Carolina Panthers. It was 2008, and Tolbert was a San Diego Charger just starting to get to know linebackers coach Ron Rivera – who would become the Chargers’ defensive coordinator that very October.

The Chargers were hosting the Panthers. Somehow, of course, Tolbert found Thomas Davis, then beginning his fourth season as a bruising linebacker with the Panthers, in the team hotel, and started jawing.

“I was talking so much trash,” Tolbert said. “You know, I was like, ‘man, when I come through there, I’m gonna bust you right in your mouth,’ this and that.”

Former Panthers defensive coordinator Sean McDermott now has his first head-coaching job in Buffalo after being hired away from Carolina last January. Former Panthers assistant general manager Brandon Beane took his first general manager job in Buffalo in May, after almost a decade with Carolina.

McDermott not only signed Tolbert in free agency this spring, but also picked up former third-string Panthers quarterback Joe Webb, another locker-room favorite, after Webb was cut by the Panthers in the preseason. Former one-year Panthers nickel Leonard Johnson, a close friend of Carolina quarterback Cam Newton last season, is now Buffalo’s nickel after also developing a close relationship with McDermott last season.

Rivera said the reunion will likely be “emotional,” but of course, it was Tolbert who may have summed things up the best.

“We’re always going to be friends,” he said. “On Sunday at 1 o’clock, for three or four hours, we’re going to be enemies.”

What Ron told Sean

Former Carolina Panthers defensive coordinator Sean McDermott, left, and head coach Ron Rivera, right, talk during practice on Thursday, January 7, 2016. McDermott is now the head coach of the Buffalo Bills.

Jeff Siner jsiner@charlotteobserver.com

Rivera says he always thinks the same thing when an assistant of McDermott’s caliber interviews elsewhere: “I hope you don’t take it.”

But when McDermott was offered the Bills head coaching job by team owners Kim and Terry Pegula after the 2016 season, Rivera supported him completely.

“When it’s an opportunity to take a big step like this, you don’t want to hold anybody back,” Rivera said. “I went through it as a young coach coming up, and I was very fortunate to have (current Chiefs coach) Andy Reid, who was all about that. So I’ve tried to be that way as well.

“In this type of situation, when you lose a guy like Sean McDermott, I knew it was Sean’s ‘ultimate.’ I knew it was what he wanted to become and he worked very hard at it.”

So instead, Rivera sent McDermott on his way with some advice. First and foremost, Rivera encouraged his former coordinator to just be himself.

“That’s what you’ve got to do,” he said. “Take all the things that you’ve learned, remember all the people you’ve learned from – but you’ve got to be your own guy. I think Sean is going to do that.”

McDermott also learned from Rivera the importance of building the right culture in a locker room.

Back in 2013, Tolbert, among other players, was a key piece in turning around the then-sinking narrative of Rivera’s head coaching career.

So when former Panthers general manager Dave Gettleman rather unceremoniously cut Tolbert last spring, McDermott scooped the fullback up. After all, the self-described (and slightly tongue-in-cheek) “heart and soul” of Carolina’s locker room had some experience in culture-building.

Adding Webb was a similar decision, McDermott said this week.

But Rivera said that the most important thing he conveyed to McDermott often was his biggest mistake: Not bringing in a former head coach in an assistant role when he began his own head coaching career in Carolina.

“That book you have with all those notes, throw that out the window,” Rivera said. “Because everything that comes up will be a first-time experience. As you guys know, I made mistakes my first two years that were learning situations for me. I still make mistakes, but not as many.

“Talking to Mr. Richardson (back then), he suggested I get a mentor in John Madden. Because Coach Madden had gone through it, and I hadn’t.

“Well, Sean went out and did that. He got (defensive coordinator) Leslie Frazier. And Leslie, Sean and I have all worked together. I think that’s something that’s very beneficial to Sean, too, is that he’s got a guy that has been through it. I didn’t have that guy, and that was my mistake.”

‘Snitches get stitches’

A chunk of this week, on both sides, has been devoted to gathering intel.

Carolina showed some – not all – of its new-look offense with its two-headed running back attack of Jonathan Stewart and shifty Christian McCaffrey last week.

Not to be forgotten is the knowledge McDermott and Beane have of current Panthers players. McDermott coached most of Carolina’s 2017 defense for at least a year, and Beane studied many of the current players’ talent, tics and tells since they were in college.

Rivera said Friday that both the offense and defense changed their hand signals and code words this week because of the large amount of overlap between the teams.

But after over half a decade together, Rivera knows McDermott’s tendencies, too. And in terms of sleuthing out scheme and wrinkles, Carolina acquired cornerback Kevon Seymour from Buffalo in the trade for speedy receiver Kaelin Clay and a 2019 seventh-round draft pick.

Panthers receiver Russell Shepard said this week that each receiver would sit down with Seymour individually for a “study session” of sorts on the Bills.

“It’s like the answers to the test,” Shepard joked. “He knows the defense, even though it’s very similar to what we do here. But from a personnel standpoint, giving us tips and kind of a heads up on certain guys.”

But Tolbert, ever the chatterbox and of course right up in the mix of things, implied this week that a fair amount of information about the Panthers was coming from him.